Field of the Invention
The present invention relates to a fuel sender device for a vehicle. More particularly, the present invention relates to a fuel sender device for a vehicle, which can prevent the abrasion of a conductor part by improving a contact between the conductor part of a resistance substrate for a fuel sender and a contact point of a contact plate from a surface contact structure to a point contact structure.
Description of Related Art
Generally, a fuel sender assembly, which forms one unit with a fuel pump, is installed in a fuel tank for a vehicle as a unit to detect a residual amount of fuel.
When the fuel sender assembly outputs different resistances according to the height of the fuel surface (hereinafter, referred to as “oil surface”), the outputted resistances are transmitted to a controller of a cluster, and a fuel gauge indicates a corresponding fuel amount by a control signal of the controller.
Hereinafter, a typical configuration included in the fuel sender assembly to output fuel sender resistances and an operation flow thereof will be described with reference to FIGS. 7 to 10.
In FIG. 7, the reference numeral 10 indicates a fuel sender assembly.
The fuel sender assembly 10 includes a fuel pump 11 disposed at an upper part, a variable resistance unit 20 disposed at a lower part, and a float unit connected to the variable resistance unit 20.
Referring to FIG. 8, the variable resistance unit 20 is mounted on the outer surface of the reservoir cup 12 mounted at a lower part of the fuel pump 11. The variable resistance unit 20 includes a resistance substrate 22 having a fan-shaped conductor part 21, and a contact plate 23 conductively contacting the conductor part 21.
In this case, as shown in FIG. 8, a pair of contact points 24 having a square block shape integrally protrudes from an inner surface of a lower end of the contact plate 23.
The float unit includes a float arm 31 connected to the contact plate 23 by a hinge and a float 32 mounted on the end of the float arm 31 and floating on the oil surface.
Accordingly, when the float 32 moves up and down according to the oil surface height of the fuel due to buoyancy, the float arm 31 angularly rotates, allowing the contact plate 23 to rotate by the same angle.
When the contact plate 24 angularly rotates, as shown in FIG. 9, the contact point 24 of the contact plate 23 slidably contacts a conductor part along the left and right sides of the conductor part while being in surface contact with the conductor part 21 of the resistance substrate 22.
Thus, as the contact point 24 moves, different variable resistances are outputted from the conductor part 21 of the resistance substrate 22. These resistances are delivered to a controller of a cluster through a cable, allowing a fuel gauge of the cluster to indicate a residual amount of fuel according to a control signal of the controller.
However, the typical fuel sender device has the following limitations.
Since the contact point (square block shape) of the contact plate repeatedly sliding-contacts the conductor part while being in surface contact with the conductor part of the resistance substrate, an abrasion of the contact point and an abrasion of the conductor part severely occur, causing the life-shortening of the fuel sensor and the mis-indication of fuel.
In other words, as shown in FIG. 10, as the contact point 24 repeatedly contacts the conductor part 21 along a predetermined section (central portion) of the conductor part 21, the contact point 24 is worn out, and the central portion of the conductor part 21 is deformed and worn out because being squashed, causing the life-shortening of the fuel sender and the mis-indication of fuel.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.